For ostomy patients with flush or recessed stomas, it has been found that if external pressure is applied in the peristomal region, sufficient protrusion of the stoma may occur to aid in the discharge of effluent directly into a collection pouch, thereby prolonging the effectiveness of the adhesive seal between the faceplate and the peristomal skin surfaces. Skin irritation and patient discomfort may also be greatly reduced.
In some cases, such pressure has been applied by means of a sealing ring formed of karaya or other soft, pliable, skin barrier material, but the deformability and cold-flowability of such a ring limits its effectiveness, or at least the duration of its effectiveness, in achieving adequate stomal protrusion. Some manufacturers of ostomy appliances have therefore introduced relatively rigid convex annular inserts or attachments for use with the adhesive faceplates of ostomy appliances. Galindo U.S. Pat. No. 4,219,023 discloses a convex insert with retaining tabs 54 for engaging the wall of a pouch 4 and a mounting member 16 to deform an annular cushion member 24 and produce stomal protrusion. However, attachment of the convex insert requires it to be sufficiently flexible so that it can be folded upon itself for insertion through the stoma-receiving opening of a pouch (or through a large drain opening at the bottom of such a pouch) and for interlocking its tabs with the edges of the pouch opening. In addition to the inconvenience associated with the insertion and attachment of such a pressure ring, there is the further disadvantage that such a ring might become disconnected in use and fail to perform its intended function.
Other constructions are known in which convex pressure ring assemblies are located along the bodyside surfaces of adhesive faceplates (see, for example, Nowak et al U.S. Pat. No. 4,834,731). While such an external construction avoids the aforementioned problems associated with the use of internal pressure rings, external arrangements tend to be relatively complex and require multiple seals between their various components. Reference may also be had to Klingler et al U.S. Pat. No. 5,330,454 which discloses a unitary ostomy appliance having a convex pressure ring, a belt attachment ring, and multiple seals between different elements of the assembly. In general, constructions that require a multiplicity of elements and seals between them not only incur greater manufacturing costs but might conceivably present increased risks of seal failure in use.
One aspect of this invention therefore lies in providing a one-piece ostomy appliance of relatively simple construction in which a single thermoplastic ring serves both as a convex pressure ring and as a belt attachment ring and in which only two concentric seals are required to join the pressure ring to both a pouch and an adhesive faceplate. Since the pressure ring is intended to be attached to a supporting belt, the pressure ring is particularly effective in distributing forces about a stoma to cause stomal protrusion as the supporting belt is tightened. The fact that only two seals are required to join the three components of the assembly together simplifies manufacturing procedures and results in cost benefits. Also, because failure (leakage) of ostomy appliances is believed to occur most frequently along seal lines or bonding zones, the provision of only two such zones is believed advantageous in terms of increased reliability and duration of possible use.
Briefly, the appliance comprises a collection pouch, an adhesive faceplate having a soft, elastomeric backing layer, and a relatively stiff convex pressure ring. The pressure ring has a first surface that faces the faceplate and includes a convex annular portion that engages the faceplate and supports the faceplate's annular inner portion in convex condition. The first surface of the pressure ring is sealingly secured to the backing layer of the faceplate along a first annular attachment zone and its second surface sealingly secured along a second annular attachment zone directly to the collection pouch about its stoma-receiving opening. In addition, the pressure ring is provided with a pair of integral and diametrically disposed belt-attachment tabs that project laterally from the ring and serve as connecting loops for the attachment of a support belt or strap.
Other features, advantages and objects of the invention will become apparent from the specification and drawings.